Dwarf plants, effect

Gibberellins have remarkable effects on many dwarf plants, such as dwarf pea, dwarf corn, and bush beans. When treated with gibberellins, these plants grow to full size. Gibberellins also affect the extent to which a plant develops side branches. 

Based on these fundamental pieces of information, the material is used on ornamentals to reduce height, producing compact plants. Additional side effects ate improved bud set and color. Experimentally, the compound has been used to dwarf fmit trees which has led to increasing the aveal planting number. 

Encecalin (I) causes a dwarfing of lettuce shoots at concentrations from lOppm and up. On the other hand, eupatoriochromene (II) causes very little dwarfing of the seedling but does inhibit germination of lettuce at lOOppm and above. The concentration of these two chro-raenes in yellow starthistle may indeed allow for some effect to be exerted on the surrounding plant community. 

California black oak and white fir and less often on incense cedar in the San Bernardino Mountains. No direct effects of oxidants have been noted on the mistletoe plant itself under field conditions. The true mistletoe obtains mainly water from its host and would be indirectly affected by debilitation of die host tree. The dwarf mistletoes Arceuthobium spp.) are common on ponderosa, Jeffry, and sugar pines in the San Bernardino National Forest. They depend on their host for both water and carbohydrates. Heavily infected or broomed" branches on ponderosa or Jeffrey pines severely injured by ozone often have more annual needle whorls retained than do uninfected branches on the remainder of the tree. The needles are also greener. It can be hypothesized that the infected branch is a carbohydrate sink where a pooling of carbohydrates occurs higher carbohydrate concentrations may be instrumental in either preventing or helping to repair ozone injury to needles on the broomed branches. In the long term, stresses from mistletoe and ozone are probably additive and hasten tree death. 

Few published data are available concerning phosfon D and its effects on plants (12,18, 21), but it is included in this report because its effect on the growth of chrysanthemums is similar to that of AMO 1618 and CCC (8). Phosfon D is effective on chrysanthemums at 1(H and 10 3 M by causing a decrease in height of the plant up to 75%. The effect is reversed by gibberellin (8). Snap beans, cucurbits, and tomatoes, which are dwarfed or shortened by the proper level of phosfon D treatment, are often injured when only slightly higher concentrations of the compound are applied (12, 21). 

Catherall, P.L. Effects of barley yellow dwarf virus on the growth and yield of single plants and simulated swards of perennial rye-grass. Ann Appl Biol 1966 57 155-162. 

Graglia, E., Jonasson, S., Michelsen, A., and Schmidt, I. K. (1997). Effects of shading, nutrient application and warming on leaf growth and shoot densities of dwarf shrubs in two arctic/alpine plant communities. Eco-sciciicc4, 191-198. 

Box (1981) classified all of the different plant species into 16 different structural types (trees, small trees, etc.) and in turn into a total of 77 plant forms (e.g., evergreen tropical rainforest trees, mediterranean dwarf shrubs, etc.). This latter classification combines form, geographical distribution, and to a certain extent function (evergreen, deciduous, ephemeral). So fundamentally there are not too many different structural types of plants, as Theophrastus noted several millennia ago. These basic forms, when coalesced into communities, certainly have an influence on land surface/atmospheric models through turbulent transfer and boundary-layer effects that are often incorporated into atmospheric exchange models. 

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